Train indication system



Aug. 17, 1926. 1,596,223

G. C. WHITNEY TRAIN INDI CATION SYSTEM Original Filed March 27. 1924VE/V TUE" Patented Aug. 17, 1926.

, rseazza GILBERT C. \VHITNEY, OF NEW YORK, N. Y.

TRAIN INDICATION SYtiTEM.

Original application filed March 27, 1924, Serial No. 702,262.

February 11, 1925.

This invention relates to train 'describers and train indicators ingeneral wherein means are provided to indicate the position or describethe movement of a train or car on a railway track and in particular tonovel means for accomplishing the aforementioned results with minimumapparatus especially when installed on tracks not equipped with a signalsystem.

This present application is a division of my co-pending applicationfiled March 27, 1924, Serial No. 7 02,262, for train indication system.

In my above mentioned applicationI have set forth, at length, thegeneral objects and operation of my invention as carried into eflect orsuperposed on existing signalled railway track territory and it isassumed that reference to said application'will be had.

In this divisional application I have shown my invention arranged in asystem of train indication, without the customary track rail insulatedjoints in general use in railway signaling and indication systems andtherefore my system readily permits the use of both rails of the trackfor the propulsion system on electrically operated railways :thus thegeneral objects appear and additional objects will be disclosed as thespecification proceeds and I will point out the novel features in theappended claims.

I have provided two figures to clearly portray the preferred applicationand simplify the operation description but I wish it to be understoodthat I do not restrlct or limit myself to such application of myinvention-it is so shown merely to disclose the broad idea underlying myinvention. It will be observed that the reference characters are notconsecutive and this is because I have preferred that this invention bedisclosed and described with the same reference characters for similarparts as my previously referred to application and thus make thisdisclosure concise as well clearly understood.

'Fig.v 1' is a diagrammatic illustration of my invention.

Fig. 2 is a diagram representing the value and variation of current flowin the indie-a tion circuits due to train travelalong the track sectien.in. 2 may also sea en-men {I b a shew variance. as r illuminatin smitDivided and this application filed Serial No. I 8,401.

ted by the indicator lamps as the train proceeds along the tracksection.

Referring to the drawing-In Fig. 1, I have shown the two rails 6, T, ofa railway track as continuous but it will be appreciat ed that they maybe made in various lengths and connected together by splice platesandbonded or otherwise to form a continuous rail circuit as is customarybut, track rails 6, 7, remain electrically insulated (in so far as theindication circuit, hereinafter eX- plained, is concerned) from eachother by the wood ties or other appropriate means in general use.

As the means rent supply on the track rails for the working of myinvention I have shown thre. transformers 9 to supply energy to thetrack at selected points, approximately though not necessarilyequidistant. Said transformers 9 receive energy from source of energysup ply alternator 18 by way of power wires 17, 16, and branch wires 15,14. The secondary windings of transformers 9 are connected to the trackrails 7, 6, by means of track wires 11, 10. Connected in series witheach of the secondary windings of transformers 9, I show primarywindings 35 of transmitter transformers 34 and inductively coupled tosaid primary windings 35, I show transmitter secondary windings 36, eachof which is included in a transmission circuit 37, 38. Included at thereceiver end of said transmission circuits I show receiver transformers39 to the secondary windings of which are shown connected indicatorlamps 42. I show track rails 6, 7, short-circuited by reactances C D Eat suitable places. approxi mately at mid-points, between the pointswhere energy supply track wires 10, 11 are connected to said trackrails. The characteristics of all apparatus is proportioned such thatthe induced current supplied to the respective indicator lamps 42 isamaximum when the track rails 6, 7, are shortcircuit-ed, as by a trainwheel shunt, at the corresponding points of energy supply trackwires 10,11, and said maximum induced current flow to the respective lamp 42varies as said train wheel shunt moves either way from said points withslow reduction until said train wheel shunt passes a trackshort-circuiting actarlce and thereafter at a rapidly ii easing rate,

rea

to impress alternating curployed, and as illustrated in Fig. 2, whereina train is assumed to be a point only for the purpose of clarity.

From the foregoing description it will be evident that the movement ofthe train is synchronously indicated by the change in illuminationcaused by the change in value of induced current supplied to said lampas the train moves along the track section and without the use ofinsulated joints in the other appropriate means track rails.

Hereinbefore, l have referred to the fact of track rails 6 and 7 beingelectrically insulated from each other by the wood ties or and it willbe evident that, even though the wood ties are an insulator when dry,they may be wet due to rain and their value as an insitilator be therebyimpaired. it is customary, therefore, to apply only low voltages to thetrack rails 6 and 7 and especially so with this type of system withoutinsulated track rail joints and with indication transmitters 3 1- atcomparatively close intervals, as dictated by the spacing betweentrains. It is the general custom to arrange the indicator lamps at acentral point for a given territory which may be of considerable extentand, owing to the great number oi circuits involved, economy demandsthat small wires be used in the transmission circuit and nat urally onlya small transmission current can be tolerated, otherwise the loss intransmission would not only be prohibitive but would interfere with theind'cation as hereinafter pointed out. Starting then, with thenecessarily low track circuit voltage I provide inductive coupling toact as a stepup transformer to provide a higher trans mission circuitvoltage and the corresponding transmission current for indicationpurposes is of the order of 0.015 ampere and less. Now, as is welll:nown, an indication lamp of high voltage and low wattage (one (1) Wattand less) is not commercially possible because of the inability toprovide a lamp filament whichwill heat on a current flow of the abovementioned order of 0.015 ampere and less and accordingly I providereceiver transformer 39 of the step-down type and wherein the resultantinduced indicating current flow to lamp 4-2 is of the order of 0.080 to0.350 ampere and at an operating voltage of from approximately one (1)volt to live (5) volts. Thus it will be evident that, in the use oftransformer 39, means have been provided to etlect an indication on avery small transmitted power and with a minimum in the losses incidentto transmission. A minimum in the losses of transmission is importantfor the reason that the var ation in currentflow in the rail circuit, asbetween the train or car at several points within the influence territorof an indication lamp, is small and every last effort must be made toconserve the results, of the variation, during transmission to theindication device.

Referring to Fig. 2, the solid irregular line traces out the value ofcurrent supply to indicator lamp 4201) as the train wheel shuntapproaches and traverses track sec tions Cl), said current reaching amaximum when. the train wheel shunt is adjacent track wires 10, 11, forthat section and reachinga practical minimum rapidly, as aforesaid, whenand as said train wheel shunt passes a short distance beyond saidsection: similarly, the dot and dash line illustrates similar conditionsfor the traclr' section and corresponding indicator lamp DE: and so onto the end of the system, as will be appreciated. Obviously, a train isnot a point and the representative lines in the diagram will broaden andoverlap as the train point takes on the dimension, length.

It will be understood that the variation in the induced current flow tothe lamp as the train wheel shunt moves on the track railsis due to thefact of the rail resistance being increased or decreased in the circuitwhich includes winding 35 for the respective section.

Vi hile, it may be assumed that the characteristic variation ofillumination is the same for train position ineach halt ot a tracksection, it will be appreciated that the direction of movement of thetrain is emphasized by the indication of the lamps for the adjacenttrack sections.

it should be noted that track reactances C D and E may be eliminated inwhich event the operation of my system will be less contrastlydistinctive.

Attention is directed to the fact that, while I have shown, in F 2, thatthe irregular lines represent the variation in currentsupply to thelamp, they also represent the variation of the illumination of therespective indicator. lamps as a car proceeds over the track section. Idesire it to be distinctly understood that, although. the irregularlines oi Fig. 2, show a variation in illumination between the extremes,as the car passes. over the track section (that is, be tween noillumination and full illumina tion) the indicator lamps may bepartially illuminated at all times, for example. with 20% illumination,when the track section is not occupied by a car, andL with illuminationvariation between 20% 'llumination as a base (at the time the car entersthe traclr section) to 100% illumination when the car wheel shunt is onthe track at the point where track wires 10 and 11 for the respectivesection are attached-all as determined by the design of apparatus ineach installation. The fact that the lamps may be arranged to bepartially illuminated at all times provides a means for continuouslyinequipped track dicating that the system is in working order.

I wish it to be understood that, while I have only illustrated twocompletely sect-ions and portions of two adjacent sections, in practicea complete territory would be equipped and the indicator lamps assembledin an indicator board or track model diagram at the desired location.

The transmission circuit 37, 58, is generally composed of No. 19 A. N.G. or smaller wires owing to the fact that on account of low wattagelamps being used the small line current permits of using smallconductors, thus contributing to low installation costs.

Obviously, the arrangements and illustrations which I have shown anddescribed are merely illustrative and do not exhaust the variousembodiments and forms which I have made, or that anyone ordinarilyskilled in this art could make without departing from thenovelty,'spirit and scope of the broad idea of means underlying myinvention.

Having thus described my claim and desire to secure by ent:

1. A train indication system; characterized by a plurality of sources ofenergy impressed upon the track rails of a railway track, each source ofenergy having an inductive coupling included in series therewith, and anindicator lamp inductively coupled to each inductive coupling, eachindicator lamp indicating the presence and movement of a car on saidrailway track, both rails of said track electrically continuous andwithout insulated joints.

2. A train indication system; characterized by a section of railwaytrack bot-h rails of which are maintained electrically coninvention ILetters Pattinuous and without insulated joints, a

source of energy impressed upon the track rails at a plurality ofpoints, an inductive coupling included in an energy supply wire to eachdicator lamp inductively coupled to each inductive coupling, forsynchronously indicating the presence and movement of a car on saidrailway track.

3. A train indication system comprised of a section of railway track, asource of energy, transformers for supplying said energy to said trackat a plurality of points, reactance elements bridging the rails of saidtrack between the points of energy supply, and means for utilizing saidenergy to indicate the presence and movement of a train on said sectionof railway track, both rails of said track electrically continuous andwithout insulated joints.

4. A train indication system comprised of a section of railway track, asource of energy, transformers for supplying said energy to said tracksection at a plurality of points, an indication transmitter connected ofsaid points, and an 111-' in series with each of said transformers, and

with each of said indication transmitters, the movement of variation inlight emitted by said lamp, both rails of said track electricallycontinuous and without insulated joints.

5. A train indication system comprised of a section of railway track,asource of energy, transformers for supplying said energy to said tracksection at a plurality of points, an indication transmitter in serieswith the energy supply to the track rails of said track, and anindication receiver for each transmitter, each transmitter responsivelycontrolling the corresponding receiver as a train moves on said sectionof railway track, each receiver indicating the movement of a train onsaid section of railway track, both rails of said track electricallycontinuous and without insulated joints.

6. A train indication system, comprised of a section of railway track, asource 0 energy, transformers for supplying said energy to said tracksection at a plurality of points, indication transmitters inductivelycoupled to said supply, a transmission circuit for each transmitter,indication means synchronously responsive to variations in the energyflow in said transmission circuit caused by the movement of a train onsaid section of railway track, both rails of said track electricallycontinuous and Without insulated joints.

7. A train indication system comprised of a section of railway track, asource of energy, transformers for supplying said energy to said trackat a plurality of points, indication transmitters inductively coupled tosaid track, and indication receivers including indicator lampsinductively coupled with said transmitters, said lamps energized fromsaid source and with partial illumination when said track is unoccupied,said illumination varying as a car moves on said track, both rails ofsaid track electrically continuous and without insulated joints.

8. A train indication system comprised of a section of railway track, asource of energy, a plurality of transformers for supplying said energyto said track at a plurality of points, transformers in series in theenergy supply to said track, transformers connected to said secondmentioned transformers, and indicator lamps connected to said thirdmentioned transformers, both rails of said track section electricallycontinuous and without insulated joints.

9. A train indication system comprised of a section of railway track. asource of energy, transformers for supplying said energy to said trackat a plurality of points, indication transmitters inductively coupled tosaid track, and indication receivers connected to said transmitters,each receiver at a train on said section by and remotely, located timesindicating the presence of a train on said track and at timescontinuously indicating the movement of a train on said track, bothrails of said track electrically continuous and Without insulatedjoints.

10; A train indication system comprised of a section of railway track, asource of en ergy, transformers for supplying said energ r to-said trackat a plurality of points, transformers in series with the secondary ofthe first mentioned transformers, transmission circuits in series withthe secondary of the second mentioned transformers, a third transformerin series with each of said transmission circuits, and indicator lampsconnected to the secondary of said third transformers, both rails ofsaid track electrically continuous and without insulated joints.

11. The invention set forth in claim 2, distinguished by the indicatorlamps being assembled to form a train indicator diagram and arranged inconsecutive order.

Signed at Brooklyn in the county of Kings and State of New York.

GILBERT C. lVI-IITNE Y.

